England will bring into force new statutory purity criteria for magnesium L-threonate monohydrate on 13 August 2026. The Department of Health and Social Care’s Explanatory Memorandum says the instrument is intended to complete the legal framework for using this form of magnesium in food supplements, while the Regulations extend to England and Wales but apply in practice in England only. (statutoryinstruments.parliament.uk) In practical terms, the measure completes the legal route from authorisation to sale. DHSC says magnesium L-threonate monohydrate cannot be lawfully sold in food supplements in England unless it is both listed as a permitted form of magnesium in Schedule 2 to the 2019 Regulations and backed by statutory purity criteria. (commonsbusiness.parliament.uk)
That sequencing is deliberate. A separate negative instrument, the Nutrition (Amendment etc.) (EU Exit) (Amendment) Regulations 2026, adds magnesium L-threonate monohydrate to Schedule 2 on 12 August 2026, and this affirmative instrument follows on 13 August because purity rules can only apply once the substance is listed. (legislation.gov.uk) The split procedure also reflects a gap in the existing rulebook. DHSC says there was neither an existing legislative specification nor an internationally accepted purity criterion available for this substance, so a dedicated statutory standard was needed to give businesses and enforcement authorities a clear legal reference point. (commonsbusiness.parliament.uk)
The Schedule is more detailed than the headline percentages suggest. It sets an assay range of 7.2% to 8.3% magnesium and 82% to 91% L-threonate, and also requires a water-soluble white powder, a pH of 5.8 to 7.0 in a 1% water solution, loss on drying of no more than 5.0%, oxalic acid or oxalate of no more than 0.5%, and maximum contaminant limits for arsenic, lead, cadmium and mercury. (legislation.gov.uk) For manufacturers, importers and local authority enforcement teams, that detail matters because the instrument does not merely authorise an ingredient name. It fixes the composition and contaminant thresholds against which batches can be assessed, in effect giving the FSA’s safety specification direct force in domestic law. (legislation.gov.uk)
The broader policy sequence began earlier in 2026. DHSC records that magnesium L-threonate monohydrate was authorised as a novel food under assimilated Regulation (EU) 2015/2283 on 5 March 2026 after assessment through the Food Standards Agency’s regulated products process, and the Commons Delegated Legislation Committee was told that the FSA concluded the substance was safe under the proposed conditions of use. (commonsbusiness.parliament.uk) Those authorisation conditions remain relevant to businesses considering the ingredient. The FSA’s regulated products entry states that use is limited to food supplements for adults aged 18 and over, excluding pregnant and lactating women, with a maximum intake level of 250 mg of magnesium per day; parliamentary debate also recorded an initial five-year exclusive use period for the applicant unless another business secures its own authorisation or permission to rely on the data. (data.food.gov.uk)
The consultation record was formal but modest. The Explanatory Memorandum says the FSA ran a nine-week public consultation from 18 December 2024 to 19 February 2025, in line with the open and transparent consultation duty in Article 9 of Regulation (EC) No 178/2002. (commonsbusiness.parliament.uk) According to the FSA’s published summary of responses, only 12 submissions were received across the wider consultation package. For magnesium L-threonate, one respondent supported authorisation without raising safety concerns, while another raised possible divergence from EU maximum levels; the FSA said it reviewed the EU position and amended its final advice so the permitted level would align with the EU while remaining within the safety assessment. (food.gov.uk)
The parliamentary route was routine rather than contested. The draft instrument was laid on 21 April 2026, debated in both Houses on 10 June, approved by the Lords on 15 June and by the Commons on 16 June, with ministers in both chambers describing it as a narrow regulatory update required to keep the food supplements regime operational once a new substance has been authorised. (statutoryinstruments.parliament.uk) For the market, the effect is limited but clear. DHSC says the amendment is optional, creates no significant new costs and did not require a full impact assessment, yet from 13 August 2026 it gives supplement manufacturers a lawful route to place products containing magnesium L-threonate monohydrate on the English market if the separate listing instrument and the new purity specification are both met. Equivalent changes have been made in Wales and Scotland, while Northern Ireland continues to apply the EU-equivalent regime under the Windsor Framework. (commonsbusiness.parliament.uk)